An apparatus that includes therein a heat emitting element such as an electric/electronic parts and units uses a fan or the like to ventilate the inside the apparatus and cool the parts and units. That keeps the inside temperature of the apparatus from rising in order to stabilize the operation of the apparatus.
There have conventionally been provided an apparatus and a method for evaluating the resistance of an object apparatus to fibrous particles (see, for example, below Patent Reference 1).
Further, there have conventionally been provided methods for producing super particles that are to be used as additives to cosmetics and food or as coating of fiber, and ground fiber that is to be used as a filler for a mold made of resin molding material (see, for example, Patent References 2 and 3).    [Patent Reference 1] Japanese Patent Application Laid-Open No. 07-120377    [Patent Reference 2] Japanese Patent Application Laid-Open No. 2006-182992    [Patent Reference 3] Japanese Patent Application Laid-Open No. 2007-098255
In the environment where an apparatus actually functions, various kinds of dusts having various sizes generated due to human life and the like flow in the air.
It is natural that most dust particularly in houses is generated due to home life. Such dust generated in house mainly contains fibrous particles having a longitudinal diameter (i.e., the length in the longitudinal length) of approximately 50-100 μm.
Air containing such fibrous particles is taken into an apparatus by a fan or the like, whereupon lint dust is clogged and accumulated inside the apparatus. That may be a cause of a rise in the temperature inside the apparatus, and finally one of the causes of breakdown.
However, a conventional method for evaluating resistance to dust mainly uses sand dust of 50 μm or smaller, but does not use dust of this kind of fibrous particle generated in houses and the equivalents for evaluation.
Generally, no method is provided which obtains fibrous particles generated in houses, or no method is established which evaluates using such fibrous particles.
It has consequently been impossible to evaluate the resistance of an apparatus to fibrous particles generated in houses.